Improvement in electro-chronographs



A. H. RUSSELL.

ELECTRO CHRONOGRAPH.

Patented March 7,1876.

Wmassaa.

Mix/@MNM UNITED FFICE.

ANDREW H. RUSSELL, 0F UNITED STATES ARMY.

IMPROVEMENT iN ELECTRG-CHRGNGRAPHS.

Specification forming part of Letters Patent No. 1174,15414., datedMarch '7, 1876, application iled February 3, 1876.

To all whom itmcty concern:

Be it known that l, Lieut. ANDREW H. RUS- SELL, of the United StatesArmy, have invented a new and useful improvement inElectro-Chronographs, ot' which the following is a full, clear, andexact description, reference being had to the drawings accompanying andforming part of this specification.

This invention is an improvement upon the Schultz electro-chronograph,in which small intervals of time are measured by means oi' a sinuousline traced by the extremity or' a tuning-fork, vibrating an ascertainednumber oi' times per second, upon the surface of a rotating cylinder,which form of chronograph isA Well known.

The tuning-fork stands in a vertical posi'- tion in front of therotating cylinder, and its vibrations are originated and sustained bymeans of electromagnets on each side of it, in the manner well known incertain forms ot' acoustic apparatus.

Means areprovided for making a mark upon the cylinder at any desiredmoment of time; but this is not necessary to describe, as myiinprovement relates to other parts of the apparatus.

The necessary alternate magnetization and demagnetization o1" themagnets which sustain the vibrationsor' the tuning-fork is caused by thebreaking and closing of the circuit by means of an interruptcrautomatically operated in such a manner that the succession of currentsis produced in unison with the vibrations of the tuning-fork, which willalways make the same number or' vibrations in each second. Thisinterrupter consists of a steel beam, one end of which is fixed to asuitable support, and the other, extending beneath an electro-magnet andover a small cup containing mercury, has a piece of platinum attached,which touches the surface of the mercury, unless the beam is drawn up bythe attraction of the magnet.

Onepole of the battery is connected with the mercury in the cup by aplatinum wire, and the other pole to the beam by a wire which forms apart ot' the circuit through the electro-magnet above the beam, andthose .on each side of the tuning-fork.

On making connection with the batter all the magnets will becomeexcited, the prongs oi' the tuning-fork will be drawn apart, and thebeam will be attracted and the platinum point raised from contact withthe mercury. This will break the circuit, the magnets will all bedemagnetized, the tuning-fork will commence to vibrate, and the bea-mwill be released and complete the circuit, as before, and thus asuccession of currents will be automatically produced.

These interruptions must be in unison With the vibrations ot' the fork,in order that the latter may continue 5 for, if not in unison, thevibrations ot' the fork would be arrested, or

retarded, rather than sustained, and conseto make, and it is found verytroublesome and difficult to maintain the interruptions of the circuitexactly in unison with the vibrations of the tuning-ieri; for any lengthof time, a very slight difference being suiiicient to retard themovement of the fork and render precision and accuracy in working withthe apparatus impossible.

To avoid the necessity for these adjustments and dispense with the useof the mercurial circuit-closer is the object of my invention, whichconsists in so arranging a spring in connection with the tuning-forkthat the latter acts as its own interrupter, whereby the construction ofthe apparatus is much simplified.

This improvement, by dispensing with the extra electro-magnet for thebeam, enables the chronograph to be operated with less batterypower thanwhen the mercurial circuit-closer is used.

In the drawings referred to, Figure 1 is a agram showing sufcient of theworking parts of a Schultz chronograph of the usual form is themercurial circuit-closer.

ble fastened to the frame M.

tounderstand my improvement. Fig. 2 is a view in elevation ot' myimprovement, showing the tuningfork and spring-interrupter in position,and the connections complete. Fig. 3`is a view showing the form in whichI con struct the spring interrnpter more full y, and Fig. 4 is anotherform ot' thc spring-interrupter.

In these figures similar letters refer to similar parts.

Referring to Fig. I, G is the cylinder ofthe chronograph, and D is thetrain by means of which it is rotated. F is the tuning'i'ork, and II Hare the magnets which originate and sustain its vibrations. F is theinterruptrn.Y and E is the magnet which operates it, and I The magnets EH H are in the same circuit which is interrupted at AI. In Fig. 2, F isthe tuning-fork.

lH H are the magnets on each side, properly supported 011 the frame G. Mis a vertical frame attached to the frame G, and A is a ta- Upon thetable A are the binding-screws by which connection is established withthe battery and inductioncoil used with the apparatus, the function ot'which it is not necessary to describe. B is a brass plate, which isfastened underneath the table by the screw d, which works through theslot g in the plate into the base oi the thumbscrew b. This screw d hasa milled head at d. e is a stripot' brass, which, at one end, is rivetedor screwed to the brass plate B underneath, and at the other end hasprojections, which serve to hold the steel spring S, which is at a rightangle to the strip c. This steel Vspring S may be a small piece ofwatch-spring.

I is a screw, which works through the plate B, against the strip c, sothat the strip can thereby be raised or lowered, thus moving the end ofthe spring S horizontally. By this means the end ot the spring S is madeto bear against a platinum. point, p, fixed on the inner side of one endof the tuning-fork. The fork and spring are connected with the oppositepoles of a battery, and the current is closed and broken at p by thevibrations of the fork. The connections are shown in Fig. 2. r is athumb-screw attached to the base of the fork, for receiving one wirefrom the battery, and

the other wire passes around the electro-inagnets to the thumb-screw Z),and thence to the having been adjusted, the circuit is completed at p bya tnrnot the screw t, and the electromagnets, becoming excited, draw theprongs ot' the tuning-fork apart. This causes an interruption oi' thecircuit at p, the fork flies back, and the circuit is again closed 5 andthus, by this automat-ic breaking and closing of the circuit, thevibrations are maintaned as long ns connection is established with thebattery. The steel spring S may be attached to the strip @by a screw, asshown in Fig. a, or any other suitable form of attachment may be used.

The adjustments necessary for maintaining the vibrations ot' the forkare readily and easily effected at the spring -interrupter, as will bereadily seen.

I am aware that it is not new to make a tuning-fork act as its owninterruptcr, such a device being found in certain forms of acousticapparatus, but in these apparatus mercurial circuit-closers have beenused. These interrupters are not suitable for use in chronographs inwhich the tuning -lork acts as its own intcrrupter, for the reason thatthey necessitate placing the tuning-fork horizontally, which is a veryinconvenient position, and therefore a spring-interrupter is the onlyform that can be used.

The form of spring-interrupter which I have described is that which Ihave found most suitable, but I do not confine myself to the use ot'this particular form, but any other form which will answer the purposecan be used, and it may be arranged in connection with the fork in anyother way besides that which I have described which will accomplish thedesired result.

What I claim as my invention to secure by Letters Patent, is

l. In an electrofchronograph, the combination, with the tuning-forkwhich marks the rotating cylinder, or a spring-interrupter,substantially as and for the purpose set forth.

2. The combination et' the tuning-fork F, having the platinum point 19,the spring-inten rnpter, consisting of the strip c and spring S, theplate B, table A, adj ustin g-screws t d, and electrical connections,substantially as and for the purpose set forth.

ANDREWv HGWLAND It Nitnessesz PETER S. Misma, S. E. TELLMAN.

, and desire Ussntt.

spring S. The connection with the battery

